Given the ever-increasing desire for mobile communications and computing, wireless local area networks (WLANs) have emerged. WLANs now support high-speed wireless communication connections to a network for various types of user terminals, including personal computers, computer peripherals, telephones, personal digital assistants, and the like. Although WLAN technology has evolved to a point where there is sufficient bandwidth to support voice and other real time sessions, capacity is still finite. As the number of users wanting to communicate increases, quality of service (QoS) mechanisms are needed to maintain desired levels of quality.
Most WLAN deployments fall under the IEEE's 802.11 standards. Although the 802.11 products do not currently have a QoS mechanism, the IEEE has proposed a QoS extension to the basic wireless LAN standards. The QoS extension applies a hybrid coordination function (HCF) to assign communication priorities to user terminals that are contending for access to a common wireless channel. The QoS mechanism is referred to as enhanced distributed channel access (EDCA).
EDCA now has four access categories, corresponding to distinct priority levels for gaining access to a given wireless channel. The four access categories are voice, video, best effort, and background. In operation, access categories are assigned to user terminals and applications that are contending for the wireless channel to transmit or receive frames of information. The access categories may be assigned by a switch or access point of the WLAN backbone network. Theoretically, the user terminals are supposed to contend for and gain access to the WLAN based on the assigned access categories. User terminals participating in a voice session are generally given greater and more frequent access to a given wireless channel than user terminals that are sending emails, which require a priority level corresponding to either a best effort or background access category.
Unfortunately, the user terminals may automatically ignore or be configured to ignore an assigned access category and use a higher priority access category than that assigned to the user terminal when contending for and gaining access to the wireless channel. The switch or access point assigning the access categories has no way of ensuring that the user terminals are abiding by the assigned access categories. When user terminals do not abide by the relative priory levels for the assigned access categories, QoS goals of the service providers and for each of the users are not met.
Accordingly, there is a need for a technique to ensure that user terminals are operating in a manner consistent with assigned access categories. There is a further need to ensure such operation in a manner consistent with existing standards.